Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations establish a non-read-only, non-destructive, non-idempotent, open-world write. The description adds real value beyond them: it discloses the dry-run default (confirm=false previews), the fact that confirm=true actually mutates, the public-URL sourcing requirement, and the returned image_id. Missing: auth/permission needs and whether re-uploading duplicates assets.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense sentences, zero filler, and the mutation-relevant confirm semantics are front-loaded after the core purpose. Nothing could be cut without losing information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be explained (image_id is a bonus). For a mutating upload tool whose annotations already carry the safety profile, the description covers the critical dry-run behavior adequately; only per-parameter and prerequisite detail is thin.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% across 4 parameters, so the description must compensate. It explains confirm (the two modes) and partially image_url ('public URL'), but says nothing about advertiser_id or file_name, leaving half the surface undocumented.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb + resource ('Uploads a TikTok image creative') plus scope constraint ('from a public URL') and output ('→ image_id'). It implicitly differentiates from upload_tiktok_video by naming the resource type, though it never names that sibling explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The confirm=false/confirm=true pairing gives genuine mode-selection guidance for how to invoke it, and the 'public URL' constraint is a usage precondition. However, it offers no guidance on when to pick this over the many other upload_* siblings (upload_image, upload_image_asset, upload_meta_image).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.